Best Fuel Injector Cleaner?

Do the OTC kits work or should u manually clean. Mechanic charges a lot to manually clean so I'm lookin at the Over The Counter stuff. Redline, STP, Pennzoil make some. What do u recommend and is there a recognizable difference?

I have use STP OTC Fuel System Cleaner and it seems to work ok.

Thanks, tho I'm sold on the Redline products.

How do you like Redline products?

everyone raves about it. they have an informative website too. havent used it yet tho but usually i dont recognize a great difference. but i like the assurance.